ByMatthew ShaerFebruary 7, 2011

Verizon this week confirmed that it would offer unlimited monthly data plans to Verizon iPhone 4 users, a stark contrast to the tiered data plans available to customers of AT&T. "I’m not going to shoot myself in the foot" by not rolling out an unlimited option, Verizon chief operating officer Lowell McAdamtold the Wall Street Journal today, adding that the unlimited option would be temporary. (No word on exactly how temporary.)

So how do the numbers break down? Well, Verizon iPhone users will reportedly pay $30 a month for unlimited data. By comparison, AT&T currently offers two data plans: The DataPlus plan, which includes 200MB of data for $15 a month, and the DataPro plan, which includes 2GB of data for $25 a month. (A caveat: AT&T used to offer unlimited data plans for $30, and if you signed up for that option originally, AT&T allows you to hang on to it indefinitely.)

Obviously, the unlimited offer is an attempt to gin up interest in the Verizon iPhone, and it may well work. But as Farhad Manjoopointed out last week over on Slate, unlimited data plans "are more expensive than pay-as-you-go plans for most people. That's because a carrier has to set the price of an unlimited plan high enough to make money from the few people who use the Internet like there's no tomorrow. But most of us aren't such heavy users."

A point of reference: AT&T estimates that you'd have to send 10,000 emails to go over its DataPro 2GB allowance. Or you'd have to click through 4,000 web pages. Anecdotally, we can tell you that we are pretty addicted to our iPhone 4 handsets, and that we have never run over our DataPro allotment, no matter how many times we click through the Huffington Post application. How about you?